Compressor



June ll, 1929. G. ANDRESEN COMPRE S SOR 5 sheets-Sheet 1 Filed June l2, 1926 NWN June 11, 1929. G. ANDRESEN NN.. M

NJN

ae@ f@ Patented June 11, 1929.

UNITED STATES PATENT OFFICE. l

GEORGE ANDRESEN, OF CHICAGO, ILLINOIS, ASSIGNOR T0 W. B. PARKYN.

COMPRESSOR.

Application led June 12, 1926. Serial No. 115,606.

My invention relates, more particularly, to compressors of the intermeshing gear type employing a sealing liquid, such as oil, for the gears, and more especlally to compressors of the character above referred to rovided-for compressing a gas, as for examp e, and preferably, a refrigerating medium, which it v1s desired be maintained as free as possible of the sealing fluid.

My objects, generally stated, are to provide improvements 1n compressors of the type' above referred t0, to the end that they will be better adapted for highly. compressing gas, and particularl a refrigerating medium; be capable o continuous' operation without danger of impairment, particularly from expansion of parts of the compressor; present the desired capacity for output within the limits of economy of structure and operation; and other objects as will be manifest from the following description.

Referring to the accompanying drawing:

Figure 1 is a view in elevation, partly diagrammatic, of a refrigerating system comprising a compressor for the refrigerant and embodying my invention.

Figure 2 is a view in longitudinal sectional view of the compressor the section being taken at the line 2 2 on Fig. 4 and viewed in the direction ofthe arrows.

Figure 3 is a broken sectional view of the sidewall-forming portion of the casing of the compressor, with the gears omitted, this view being taken at the line 2-2 on Fig. 4 and viewed in the direction'of the arrows.

Figure 4 is a section takenat the line 4 -4 on Fig. 2 and viewed in the'direction of the arrows; and Figure 5, a plan section taken at the irregular line 5-5 on Fig. 2 and the line 5 .on Fig. 4, and viewed in the direction of the respective arrows.

Referring to the particular illustrated em- Y bodiment of my invention, the compressor, as

a unit, is designated at 10 and comprises a4 casing shown as formed of a central section 11 presenting a base portion 12 and endforming sections 13'and 14 secured to the sect-ion 11 by bolts 15 passing lthrough these sections.

The section 11 contains parallel bores 16 and 17 of uniform diameter throughout their length, these bores opening into each other along their adjacent edges, .as shown i-n Fig.

' 4 and each being of circular shape in cross section except where their side walls intersect.

The rotary element of the compressor is of the herring-bone gear type comprising the gear elements 18 and 19 whichrotatably it the bores 16 and 17, respectively, and are journalled at shafts 2O and 21 thereon in the end sections 13 and 14. The gear element 1,8

these gears being effected through the medium of the shaft 20 one end of which is extended,`

as represented at 20, at which it projects .through a stufng box 26 on the casing sec- Y tion 13.A

The casing section 11 at oppositesides of the line of intermesh of the teeth of the gear elements 18 and 19, contains a gas-inlet port 27 and a sealing-fluid inlet-port 28, these ports being centrally located relative to the line of division between the gear sections of each gear element and the axes of these gear elements, as represented in Figs. 3, 4 and 5, the port 28 thus being in accurate registration with the point of initial intermesh of the gear elements, or in other words, in registration with these gear elements at the point where compression of the gas begins. The gas-inlet port 27 is preferably of general diamond shape as shown in Figs. 3 and 5 and extends equidistantly'beyond the line of division be-` tween the' gear sections of the respective gear elements in a direction lengthwise of the casing and short of the ends of the bores 16 and 17. The port 27 is shown as opening into a pair of passages 29 which, in turn, open into a chamber 30 in the section 11 in communica- I tion with a passage 31 which opens into a pipe 132 through which the lgas to be compressed is supplied to the compressor. The outlets for the gas compressed by the compressor are represented at 32 and 33 and open into pipes 34 and 35, respectively, through which the compressed gas is conducted away from the compressor, these outlets being provided in the casing sections 13 and 14,y respectively, and so disposed that they register with the teeth of the gear elements at their points of final intermesh. y

B way of example as regards the proportioning of the several parts of the compressor, it may be stated that for compressing sulphur dioxide to about sixty pounds pressure at the rate of approximately threequarters of a cubic foot per minute, the gears revolving at approximately eighteen hundred revolutions per minute, and with zero pressure at the gas inlet, each gear to produce the most satisfactory results should be approximately three inches long and one and oneeighth inches over-all diameter, and the gas inlet disposed, and of the shape, as shown, should be approximately one inch in length.

Referring now to the particular illustrated apparatus of which the compressor above described is an element: The compressor is shown as driven from an electric motor 36 connected with the outer end of the shaft extension 20zal on which latter an air-circulating fan 37 is mounted. The apparatus shown is of the closed circuit type in which the refrigerating medium is first compressed in gaseous form, then cooled and thereupon permitted to expand into the cooling portion of the course to perform the refrigerating function in which the refrigerant again becomes expanded and from which it passes into the compressor to be again compressed. In the arrangement shown the pipes 34 and 35 through which the compressed gas discharges rom the compressor, communicate with a pipe 38 which opens into a separator chamber 39 containing in its upper portion a gas outlet in communication with a pipe 40 which connects with the upper end of a condenser 41 in which the compressed gas is liquefied and from which it discharges through a pipe 42 into a receptacle 43 having an out et pipe 44 communicating with an expansion-valve 45 opening into the pipe 132 the portion thereof between the expansion valve 45 and the pump constituting the' refrigerating portion of the apparatus. This portion of t e apparatus is shown diagrammatically, it being understood that in practice the pipe 132 ma be provided as a coil, or in any'other suita le form, to present the area necessary for affecting the desired refrigerating action by the gas introduced therein through the expansion valve.

The port 28 communicates with one end of a pipe 46, the opposite end of this pipe connecting with the lower end of the separator 39. The pipe 46, between its ends, is formed into a flat spiral as represented at 47, the pipe 46 operating to conduct sealing liquid under a head pressure produced by the gas in the separator 39, from the bottom of the separator 39, to the gear elements 18 and 19 through the port 28.

The motor 36, fanv37, compressor 10, coil pipe section 47, condenser 41, and liquid refrigerant storage tank 43 are shown as substantially aligned within a casing or sheathing 48 open at its opposite ends and provided primarly for the purpose of localizing the flow of wir induced by the operation of the fan 37, so that the maximum cooling effect of the air on these parts will be obtained, namely, to keep the motor and compressor cool and augment the cooling effect of the condenser 41 and the oil pipe spiral 47 and receptacle 43, to enhance the liquefaction` of the compressed gas and maintain the sealing fluid in a condition in which it presents the desired viscosity.

Referring now to the operation of the compressor, it will be understood that in the operation of the gear elements 18 and 19 in the direction of the respective arrows in Fig. 4, gas is sucked in through the port 27 from which itl enters the spaces between the teeth of the gear elements at. this side of the axes thereof, and is carried around with these gears, as the latter rotate, and in the intermesh of the teeth of these gears becomes highly compressed, and finally discharges, in highly compressed condition through the outlets-32 and 33 at the ends of these gears, the sealing liquid being supplied to the gears through the port 28 by the head pressure referred to.

The feature. of providing an inlet for the gas which extends only part way along the gears, is of great advantage in the practical operation of the compressor. By this feature the area of the gears exposed to the incoming gas is greatly reduced and thus large gears presenting relatively large areas which extend beyond the ends of the gas inlet 27, may be provided whereby the heat generated in the operation of the compressor is dissipated along the gears at such a rapid rate that undue heating of the gears,and consequently undue expansion resulting in the bottoming thereof and extreme friction between the movablel parts, is avoided. Thus the gears may be provided to more closely intermesh initially than in the case of those constructions wherein the gas inlets extend the full length of the gears, and with provision of gear area sufficient to satisfactorily dissipate the heat produced by the operation of the compressor.

A further advantage arising from this feature'consists in the reduction of the amount of gas previously compressed and carried over by the gears to the low pressure, or inlet, side and the consequent increased efliciency of the pump. In explanation of this advantage it may be stated that the density of the gas between the intermeshing teeth of the gears progressively increases from a point midway between the ends of the gears toward the ends of the latter and thus the sealing fluid in being carried over by the teeth of the gears from the high pressure side to the low pressure side contains gas under progressively increasing densities, and in progressively increasing proportions, the sealing fluid containing gas at the greater density and of greater volumeadjacent the ends of the gears; and if such of CSI the gas as is thus carried over enters the gas inlet of the compressor it immediately expands and thereby displaces the gas enterin the gas inlet and consequently reduces the eficiencyA of the apparatus. By the above-referred-to feature of my invention those portions of the gears at which the oil is most highly impregnated with high density gas, are out of registration with the gas inlet 27, and because of the close fit-between the gearcasing and the gears, impedence to the passage of this gas to the gas inlet 27 from the above-referred-to portions of the gears is reduced to the minimum, thereby greatly increasing the efficiency of the compressor.` Furthermore, by providing the sealing-liquid inlet 28 at the point of initial intermeshing of the gears im regnation of oil by the refrigerant before e ective sealing of the gears at the point of intermesh, is avoided thereby minimizing the impregnation of the oil with gas, thus increasing the eliiciency of the compressor.

Another advantage arising from the feature referred to is that, because of the barrier between the gas-outlets and gas-inlet and formed by those portions of the casing which' closely lit the gears beyond the ends of the,

gas-inlet, leakage of gas from the outlets to the inlet is greatly reduced, with manifest advantage in operating efficiency.

A further advantage obtains in the embodiment of my invention in a spiral gear structure, in that additional cooling eEect of the gears is produced by the expansion of the incoming gas along the gears, when the gas is supplied under pressure to the compressor,

following the movement of the teeth out ofregistration with the gas inlet 27 and before registering with the gas outlets 28.

Furthermore, as to such of the highly compressed gas as may be carried over wlth the oil around the outer ends of the gears and which does not again reach the gas inlet 27, it is subjected, in such highly compressed condition, to the compressing action of the gears 'and further compressed before discharge through the compressed gas outlet; and thus as to this gas the compressor operates to effect a two-stage compression, with the manifest advantage.

While I have illustrated and described a particular construction embodying my invention, I do not wish to be understood as intending to'limit it thereto as the same may be variously modified and altered without departing from the spirit of my invention; thus, by way of example, the' relative length of the gas-inlet and the gears may be, and should, be, for most satisfactory operation,` varied, depending on the degree to which the gas is to be compressed, and assuming that the same gas under the same pressure at the inlet is to be pumped;D for producing greater pressure the distance from the compressed-gas outlet to the gas-inlet being made greater, and for producing lesser pressure this distance made shorter; it being understood that where the motive force applied to the gears for rotating them is increased, the eective gear area along which the heat generated by the operation of the compressor is dissipated, should be increased by making the distance from the gas inlet tothe outlet end of the gears greater; the idea being to so proportion the gears vand the l s inlet that s uicient effective 'gear area wil be provided to effect suiicient heat dissipation to prevent vharmful mechanical friction, but without unduly sacrilicing eiiiciency of the compressor. This is .accomplished by proportionating the. parts as to size and relative location, depending upon the particular conditions to be met, as for example the kind of gas to be compressed, the pressure to which it is to be compressed, the pressure at the inlet and the degree of force to be utilized for driving the gears.

Furthermore, while I have illustrated and described my invention as embodied in a structure wherein the gas outlet is located at the end of the gear structure and the gas inlet at the side thereof, I do not Wish to be understood as intending to limit it thereto, as certain'features of my invention are capable of utilization in a spiral gear structure in which the gas ent-ers the end portion, or portions, ofthe gear structure, and the gas outlet is at the sideV of the gears, in which case the-gears would be rotated reversely to the direction of rotation of the gears in the structure illustrated.

What I claim as new, and desire to secure by Letters Patent, is:

1. Ina compressor, the combination of a casing and intermeshing spiral gears journalled to 'rotate therein, said casing containing ports at an end thereof and at a side ofsaid gear structure and closely itting the sides of said gears between said ports, eX- cept at their points of intermesh, to form a barrier between said ports.

2. A gear-compressor comprising, in combination, a casing and intermeshing spiral gears journalled to rotate therein, said casing containing a gas-inlet and a compressedgas outlet, said gas-inlet being so located relative to partially intermeshed gears from which position the gears move away from each other that these intermeshed portions move out-of registration with said gas-inlet while in intermeshed condition, thereby, enlarging the gas-pockets presented by these gears and permitting the gas therein to expand, said gas-inlet and compressed gasoutlet being located at opposite ends of said gears.

3. A gear-compressor comprising, in combination, a casing and intermeshing spiral gears journalled to rotate therein, said casing containing a gas-inlet, a compressed-gas l therein to expand.

4. A gear-compressor comprising, in combination, a casing and intermeshing spiral gears journalled to rotate therein, said caslng containing a gas-inlet, a compressed-gas outlet and a sealing-liquid inlet, said gasinlet and said sealing-liquid inlet being at opposite sides of the line of intermesh of the teeth of said gears and said compressed gasoutlet being located at an end of the gear structure, said as-inlet being so located relative to partialy intermeshed gears from which position the gears move away from each other that these'intermeshed portions move out of registration with said gas-inlet While in intermeshed condition, thereby enlarging the gas-pockets presented by these gears and permitting the gas therein to expand.

,A 5. A gear-compressor comprising, in combination, a casing and intermeshing spiral gears journalled to rotate therein, said casing containing a gas-inlet and a compressed gas outlet, said compressed-gas outlet being located at an end of said gear structure and said gas-inlet extending along said gears but I, short oi the end thereof at which said gas- A permitted to expand.

outlet is located, said gas-inlet being so located adjacent the gears at the point where teeth of adjacent gears are partially inter- Ineshed and from which position the gears move away from each other that as these intermeshing teeth move out of registrationwith said gas-inlet the gas-pockets presented by said gears enlarge and thus the gas contained therein is permitted to expand.

6. A gear-compressor comprising, in combination, a casing and intermeshing spiral .gears journalled to rotate therein, said casing containing a gas-inlet. a compressedgas outlet and a sealing-liquid inlet, said compressed-gas outlet being located at an end of said gear structure and said gas-inlet extending along said gears but short of the end thereof at which said gas-outlet is located and said gas-inlet being so located adjacent the gears at the point where teeth of adjacent gears are partially intermeshed and from which position the gears move away from each other that as these intermeshing teeth move out of registration with said gasinlet the gas-pockets presented by said gears enlarge and thus the gas contained therein is 7. A gear-compressor comprising, in combination, a casing and' intermeshing spiral gears journalled to rotate therein, said casing containing a as-inlet, a compressed-gas outlet and a sea ing-liquid inlet, said gas-inlet and said sealing-li uid inlet being at opposite sides of the line oil intermesh of the teeth of said gears, said compressed-gas outlet being located at an end of the gear structure, and said gas-inlet extending along said gears but short of the end thereot` at which said gasoutlet is located and said gas-inlet beinfr so located adjacent the gears at the point w 1ere teeth of adjacent gears are partially intermeshed and from which position the gears move away from each other that as these intermeshing teeth move out of registration with said gas-inlet the pockets presented by said gears enlarge and thus the gas contained therein is permitted to expand.

8. A gear-compressor comprising, in combination, a casing and intermeshing spiral gears journalled to rotate therein, said casmg containing a gas-inlet, a compressed-gas outlet and a sealing-liquid inlet, said gas-inlet and said sealing-li uid inlet being at opposite sides of the line oil intermesh ofthe teeth of said gears, said sealing-liquid inlet opening into the interior of said casing at the point of initial intermesh of said gears, said compressed-gas outlet being at an'end of said gears and said gas-inlet extendin` along said gears throughout a portion only of their length and so located adjacent the gears at the point Where teeth of adjacent gears are partially intermeshed and from which position the gears move away from each other that as these intermeshing teeth move out of registration with said gas-inlet the gaspockets presented by said gears enlarge and thus the gas contained therein is permitted to expand.

9. A gear-compressor comprising, in combination, a )casing and intermeshing herringbone gears journalled to rotate therein, said casing containing a gas-inlet and compressedgas outlets at the ends of the gear structure,

-said gas-inlet extending along said gears throughout a portion only of their length and so located adjacent the gears at the point where teeth of adjacent gears are partially intermeshed and from which position the gears move away from each other that as these intermeshing teeth move out of registration with said gas-inlet the gas-pockets presented by said gears enlarge and thus the gas contained therein permitted to expand.

10. A gear-compressor comprising, in combination, a casing and intermeshing herringbone gears journalled to rotate therein, said casing containing a gas-inlet, compressed-gas outlets at the ends of the gear structure and a sealing-liquid inlet, said gas-inlet and said sealing-liquid inlet being located at opposite sides of the line of intermesh of the teeth of said gears and said gas-inlet extending bination, a casing and intermeshing along said gears throughout a portion only of their length and so located adjacent the gears at the point where teeth of adjacent gears are partially intermeshed and from which position the gears move away from each other that as these intermeshing teeth move out of registration with said gas-inlet the gas-pockets presented by said gears enlarge and thus the rgas contained therein is permitted to expand.

11. A gear-compressor comprising in combone gears journalled to rotate therein, said casing containing a gas-inlet and compressedgas outlets at the ends ofthe gear structure, said gas-inlet extending alone said gears, but shortof the opposite ends oi? said gears and so located adjacent the gears at the point Where teeth of adjacent gearsare partially intermeshed and from which positionthe gears move away from each other that as these intermeshing teeth move out of registration with said gas-inlet the gas-pockets present-ed by said gears enlarge and thus the gas contained therein is permitted to expand.

12. A gear-compressor comprising, in combination, a casing and intermeshing herringbone gears journalled to rotate therein, said casing containing a gas-inlet, compressed-air outlets at the endsof the gear structure and a sealing-liquid inlet, said gas-inlet extending .along said gears but short of the opposite ends of said gears and being so located adjacent the gears at the point where teeth of adjacent gears are partially intermeshed and from which position the gears move away from each other that as these intermeshing teeth move out of registration with said gasinlet the gas-pockets presented by said gears enlarge and thus the gas contained therein is permitted to expand.

13. A gear-compressor comprising, in combination,a casing and intermeshing herringbone gears journalled to rotate therein, said casing containing a gas-inlet, compressed-gas outlets at the ends of the gear structure and a sealing-liquid inlet, said gas-inlet and said sealing-liquid inlet being at opposite sides of the line of intermesh of the teeth of said gears and said gas-inlet extending along said gears but short of the opposite ends of said gears and so located adjacent the gears at the point where teeth. of adjacent gears are partialy intermeshed and from which position the gears move away from each other that as these intermeshing teeth move out of registration with said gas-inlet the gaspockets presented by said gears enlarge and thus the gas contained therein is permitted to expand.

14. A gear-compressor comprising, in combination, va casing and intermeshing herringbone gears journalled to rotate therein, said casing containing a gas-inlet, compressed-gas outlets at lthe ends of the gear structure and herringa sealing-liquid inlet, said gas-inlet and said sealing-liquid inlet-being at vopposite sides of the line of intermesh of the teeth of said gears, said liquid-seal inlet opening into said casing at the initial points of intermesh of the teeth of the ears and said gas-inlet extending along said gears throughoutaportion only of their length and so located adjacent the gears at the point where teeth of adjacent gears .are artially intermeshed and from which positlon the gears move away from each other that as these intermeshing teethmove out of registration with said gas-inlet the gas-pockets presented by said gears 'enlarge and-thus the gas contained therein is permitted to expand.

15. A gear-compressor comprising, in combination, a casing and intermeshing herringbone gears journalled to rotate thereinsaid casing containing a gas-inlet, compressedgas outlets at the ends of the gear structure and a sealing-liquid inlet, said gas-inlet'and said sealing-liquid inlet being at opposite sides of the line of intermesh of the teeth of said gears, said-'liquid-seal inlet opening into said casing at the initial points of intermesh of the teeth of the gears and said gas-inlet extending along said gears but short of the opposite ends of said gears, said as-inlet being so located adjacent the gears at t e point where teeth ofadjacent gears are partially intermeshed and from which position the gears move away from each other that as these intermeshing'teeth move out of registration with said gas-inlet the gas-pockets presented by said gears enlarge and thus-the gas contained therein is permitted to expand.

16. A gear-compressor comprising, in combination, a casing and intermeshing herringbone gears journalled to rotate therein, said casing containing a gas-inlet, compressed- -gas outlets at the ends of the gear structure and a sealing-liquid inlet, said gas-inlet and said sealing-liquid inlet being at opposite sides of the line of intermesh of the teeth of said gears, said liquid-Seal inlet opening into said casing at the initial points of intermesh of the teeth of the gears and said gas-inlet being located at the apex portions of said gears and extending at substantially equal distances beyond said apex portions, but short of both ends of the gears and so located that it extends adjacent the point where teeth of adjacent gears are partially intermeshed and from which position the gears move away from each other and in partially intermeshed condition move out of registration with said 'sides of said gears between sai gears to form a barrier between said ports.

18. A gear compressor comprising, in combination, a casing and intermeshing spiral gears journalled to rotate therein, said casing containing a gas-inlet and a compressed-gas outlet, said gas-inlet being so located relative to said gears that it registers only with teeth in mesh at the inlet side of the compressor, said gas-inlet and said compressed-gas ontlet being located at opposite ends of said gears thereby creating a barrier to prevent loss of gas at ends of the gears.

19. A gear compressor comprising, in combination,` a casing and intermeshing spiral gears journalled to rotate therein, said casing containing a gas-inlet and a compressedas outlet, said gas-inlet being'so located relative to said gears that it registers only with teeth in mesh at the inlet side of the compressor, said gas-inlet and said compressed-gas outlet being located at opposite ends of the gears, on at the end face of the gear structure and the other at the side face thereof, thereby creating a barrier to preventloss of gas at ends of the gears.

20. A gear-compressor comprising in combination, a casing and intermeshing herringbone gears journalled to rotate therein, said casing containing compressed-gas outlet and gas inlet ports at the ends of said gear structure and between the ends thereof, respective- 1y, the gas-inlet being so located relative to partially intermeshed gears from which position the gears move away from each other that these intermeshed portions move out of registration with the gas inlet While in intermeshed condition, thereby enlarging the gas pockets resented by these gears and permittin t e gas therein to expand.

21. gear-compressor comprising, in combination, a casing and intermeshing spiral gears journalled to rotate therein, said casing containing a gas-inlet and a'compressed-gas outlet7 said gas-inlet being so located relative to partially intermeshed gears from which position the gears move away from each-other that these interm'eshed portions move out of registration with said gas-inlet while in intormeshed condition, thereby enlarging the gas-pockets presented by these gears and per mittinfr the gas therein to expand, said compressed gas outlet and said gas-inlctbeing located at one end and a side of the gear structure, respectively and said casing closely fitting the sides of said gearsbetween said inlet and outlet, except at their points of intermesh, to form a barrier between said ports.

22. A gear-compressor comprising, in cornbination, a casing and v intermeshing spiral gearsjournalled to rotate therein, said casing containing a gas-inlet, a compressed-gas outlet, and a sealing-liquid inlet, said gas-inlet being so located relative to partially intermeshed gears from which position the gears move away from each other that these intermeshed portions move out of registration with said gas-inlet while in intermeshed condition, thereby enlarging the gas-pockets presented by these gears and permitting the gas therein to expand, said compressed-gas outlet and said gas-inlet being located at one end and at a side of the gear structure, respectively, and said casing closely fitting the sides of y V GEORGE ANDRESEN. 

